I believe if we are going to permanently close the rifts, we'd need to steal the green cocaine. We can't stop him from creating a new machine to bind the spell to, we can't stop him from re-casting casting the spell that Amat taught him to link the spheres. I dont' believe we can steal it an keep it securte from him. So, to that end - we either have to eliminate him or follow his plan to free the heroes. I suspect they would do better than we can.
I see no other way out of this mess.
Also - we can't travel 5000 miles to the permanent gate. And he can't send us directly home. So again. leads me back to following his suggestion. Ideally, we free the heros, and sucker the other back here to be destroyed. Please.. we'd be doing the multi-verse a favor in releasing the Dieties of Protection.
Turing to Izad.. " if we help you, I want all the knowledge you have on the God of Lost Knowledge"